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1G Timing tensioner does not seem to sit centered with arm

Just wanted to make sure that the timing tensioner is supposed to sit where it is currently at. There seems to be a groove that looks like it would be for the tensioner plunger, but its not really close to sitting it it. The engine timing marks all seem to line up and the tension is good. The engine also rotates freely.

I am going to post some pictures of my timing marks as well as the plunger to make sure everything is normal. Thanks.

Something is off I've never seen a tensioner offset on the tensioner arm assembly like that. It's partially hanging off. And it seems that your crank trigger plate timing mark is off (little low). Did you use an after-market front case? How did you verify the #1 Piston was at top dead center? When I time an engine I use a dial gage to verify TDC. Or you could use the piston stop method. Anyway it looks like the timing is off. I would redo it. Good luck.

Something is off I've never seen a tensioner offset on the tensioner arm assembly like that. It's partially hanging off. And it seems that your crank trigger plate timing mark is off (little low). Did you use an after-market front case? How did you verify the #1 Piston was at top dead center? When I time an engine I use a dial gage to verify TDC. Or you could use the piston stop method. Anyway it looks like the timing is off. I would redo it. Good luck.

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Yes I did use an after market front case. It's an ACL/orbital. And the piston seems to be at TDC right where the mark currently is. I used a screw driver to check and it's right at the point before the piston starts to go down.

As far as the timing tensioner I'm not sure what I would do to make it sit centered. It's not quite hanging off, but it is close. I'm wondering if due to the aftermarket case or something that is just where it is going to sit...

Here is another picture of how it is sitting. The thing is, the timing tensioner pulley and the idler pulley seem to be sitting perfectly straight. Which I feel like is the more important thing. If I used a washer or something to space out the tensioner arm, it would throw them off.

Are the plastic bushings still inside the tensioner arm? They do slightly space the tensioner arm out while keeping the arms lined up, should be one for front and rear of the arm and are easy to lose.
Bad pic and editing, but these are what I'm referring to.

Thanks! Knowing me I would forget . I ordered a new one since I doubt re using the old one is a good idea. You thing ACL would give you one...

Does anyone know if that notch in the tensioner arm pictured above is there from the factory? I just want to make sure that it is not worn into the metal somehow and is supposed to be there. If that is where the tensioner is supposed to sit, then it actually seems to be in the right place.

Does anyone know if that notch in the tensioner arm pictured above is there from the factory? I just want to make sure that it is not worn into the metal somehow and is supposed to be there. If that is where the tensioner is supposed to sit, then it actually seems to be in the right place.

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A new one has a straight machined surface. it looks like its been used a lot. Its possible the bushing in the tensioner arm is worn too. You won't know until you start the engine and see if the belt off to one side on the cam gears. A new tensioner arm and bracket solved my problem.

A new one has a straight machined surface. it looks like its been used a lot. Its possible the bushing in the tensioner arm is worn too. You won't know until you start the engine and see if the belt off to one side on the cam gears. A new tensioner arm and bracket solved my problem.

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I would not mind replacing it, however it is a discontinued part and I can't find a new one anywhere.

MD195094 - there are a couple new listings on ebay. This is for 6 bolt.

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Thanks. I was hoping to just be able to purchase the tensioner arm. I guess I might have to get the whole thing. The fact that the indentation is not supposed to be there does not sit right with me.

Just ordered one from STM. Hopefully it will be here by Friday. Im planning on dropping the motor in this weekend if all goes to plan. The tensioner arm had a little side to side play in it as well so I don't want to chance it. I really did not want to spend the $100 but it is not worth risking an entire build over.

Well apparently STM is out of stock on the whole assembly as well. It does not appear that there are any new ones left, as my local stealership said that there are none in the country. I think I may have someone local that has a good used one im going to check out tomorrow. Hopefully that works out.

I talked to some other people and they did say that some of them have the indentation cast in to the arm, and some do not. Maybe it just depends on the mold used. Either way I am replacing it due to the worn bushings.

I talked to some other people and they did say that some of them have the indentation cast in to the arm, and some do not. Maybe it just depends on the mold used. Either way I am replacing it due to the worn bushings.

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In my experience on the two cars that I replaced the tensioner arm on it was from slack in the belt misadjusted tension allowing for the Piston of the tensioner to repeatedly tap the tensioner arm flange. The Talon that I put 75000 miles on and replaced the tensioner arm when I first got it and another belt on it 20000 miles ago didn't have any signs of that dimple. The original tensioner arm that I replaced had the giant dimple in it like yours and it also had the belt walking off the cam gears because the bushing was completely worn and had play in it, in and out. I saved that engine and the valves when I first got it because of how poorly the timing and tensioner had been done. It was one startup away from destroying the valves.

People may not like the answer but, every arm I come across I take to the bench grinder and make them flat again. The dent is not suppose to be there. After almost 175 4g63's built, I have yet to have an issues with removing a small amount of material.

It used to be common to weld up the divot/dimple on the arm to bring the surface back up. Grind that back down flush, not the arm.

By the time the third belt was due the arm and post had worn enough that the belt started walking leading to the full replacement.

If in fact all the OEM parts are gone I suspect a good machine shop could renew both the post on the mount and the bushings in the arm, filling the hole while they are at it.

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Does the actual post wear down? Or just the bushings in the arm? I picked up a used arm today and it has much less play, but there is still a tiny bit. Once the belt is tensioned however, there is no play anymore. The one I just installed does have a dimple in it that I just left. Does the dimple actually hurt anything?

As I understand the tensioner is fully compressed when the engine is running. And when stopped it pushes on the arm to take up the slack. So, in essence, the post and bushing would be most important for belt alignment.

As I understand the tensioner is fully compressed when the engine is running. And when stopped it pushes on the arm to take up the slack. So, in essence, the post and bushing would be most important for belt alignment.

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I know it's important, I just did not think that the post would actually wear down. I just figured only the bushings would. I might just leave it the way it is now and see if the belt is walking. If it is I'll just have to find a good one and replace it with the engine in the car.

I know it's important, I just did not think that the post would actually wear down. I just figured only the bushings would. I might just leave it the way it is now and see if the belt is walking. If it is I'll just have to find a good one and replace it with the engine in the car.

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That's basically what I did, trial and error. I went from missing timing cover tin, to pinching front case gasket, to two different tensioner arms, and I want to say the post had some wear but I dont recall the micrometer numbers. In the end, after redoing the timing belt several times in the car, a new bracket assembly looked more appealing.

I have a new arm I bought as part of the normal maint before I discovered that the belt was walking and found the wear on the post. When you buy the mount is comes with an arm so I still have the other and the tensioner pulley that also comes with.

I think I might have posted pics of the post back when I found it but I can't find them here or on my systems here.

As I understand the tensioner is fully compressed when the engine is running. And when stopped it pushes on the arm to take up the slack. So, in essence, the post and bushing would be most important for belt alignment.

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No it works like a typical spring loaded belt tensioner. The hydraulic tensioner sets the pressure of the belt tension, the pulley determines the depth of the hydraulic tensioner on the arm

Long story short, I set belt tension too tight on the pulley and I was able to hear and see the timing arm hitting the hydraulic tensioner. That is how the arm becomes grooved like in his picture

Also to note, never leave the car in gear without the parking brake on. This can cause the damage seen in the arm. The engine is being forced by gravity to apply the force of the car against the rotation of the engine. Causing the arm and all of the timing components to take that force. Really hard on the entire engine

I have a new arm I bought as part of the normal maint before I discovered that the belt was walking and found the wear on the post. When you buy the mount is comes with an arm so I still have the other and the tensioner pulley that also comes with.

I think I might have posted pics of the post back when I found it but I can't find them here or on my systems here.

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The post on mine did not have any visual signs of wear. It was also smooth.

I didn't notice the belt walking before I took the engine apart. All seemed well. Since I replaced the tensioner arm with a better condition one I'm hoping it will be okay.

Is a slight amount of side to side play normal with no tension on the arm? I'm assuming there must be some sort of tolerance/clearance.

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